Variable condenser



JNVENTOR F flmq 76,; ATTORNEYS .l. PARKIN, JR. VARIABLE CONDENSER.

APPLICATION mm MAR. 29, I920.

Patented Oct. 24, 1922.

' Jazz, BY M WIT NESS of San Rafael of Californie, have invented a new and use- Th Patented Oct. 24, 1922.

UNITED STATES 1,433,224 PATENT orrics.

-- some ream, m... or en? RAFAEL, camronma.

VARIABLE CONDENSER.

Application filed men 29,- 1920. Serial No. 369,562.

Z '0 all wlwmit may Be it known that I, Joan Pm, Jr a citizen of the United States and a resident oounty oi. Marin, and State ful V'eriablegondenser, of which the following is adescri tion. 7

My invention re atesto .deyices' for veryin%)the capacity ,inan electric circuit.

wing to the large nuznher of persons engagedin experiments in electric arts esecially in radiosighaling, there is a. great emand 'for ..a variable capacity device which is of rugged simple construction and capableof being made snd sold at a very low price. One of the ob'ects ofm invention therefore "is to provi e s ar-is. is condenser to supply this demand, imdjin which the elementserercduced to the least ossible number andare of greatest possi is sim- Another ob'eetof the-invention is to pro- 'vide a 'variafb efoondenserzofjbnlanoed construction andone which is "not easily damaged by rough handling. Another, ohject is to prorideacondens'er of large capacity for its size.

The inyentionpossesses other objects and features of advantage some of which, with the foregoing, will he set forth in the following descr ption of the referred form of my invention which is i hcilstrated in the drawin accompanying an forming part of the Edecification. It is to be understood that I do not limit myself to the showing made by the said drawings and description as I may adopt variations of .the preferred form within the scope of my invention as set forth in the claims.

Referring to the drawings: V

Figure 1 is :1 Vertical section through the center of my variable condenser. Tbe'condenser is shown mounted upon a panel, the parts being in the position of maximum capacity. Figure 2 is a rear elevation of the variable condenser, the parts being in the position of minimum capacity. Figures 3 and at. are vertical sectional views showing modified forms of my device.

My variable condenser com rises two housing disks2 and 3 of non-con uctmgnraterial spaced apart at the center and periphcry by the annular rings 4 and o respectively. The center spacm ring is o f'conducting and the peripheral spacing I'lllg of non-conducting material. A dielectr1c,prefthe housin" disks.

erably a thin disk 7 of mica, lies between the annular spacing ring and the disk 2 and u semi-circular metallic plate 8 preferably of toll, is inter osed between the disks 2 and 7. e foil w ich preferably is adhcsively united to the dielectric disk, extends outwardly and. is turned about the periphcry of the disk 2 so as to establish electrical .oontact with the annular metallic flanged rim 9, which binds the peripheral edges of A binding post 12 passin t-hrou ii the rim provides means for attac in e conductor 13, comprising one side 0 an electric circuit. Instead of using a separate plate 8 adhssively united to the disk '4', I may deposit on a portion of the dielectric disk, a metallic coating, thus bringing the metal into the closest possible contact therewith.

,;Pas'sed throu h the center of the device and securing t e parts firmly together at that point is a metallic, grommet or eye 14 which is in electrical contact with the annular rin ?i 4.

The Vevice is mounted on a shaft 16 journaled in the panel 17, and digitally controlled by a knob 18 in which the outer cud. of the shaft is embedded. The other end of the shaft {M18865 through the grommet 14 and is fixec therein hr nuts 19 on each side. A spring 21 on the shaft is interposed between the nut 19 and the solder plate 22 lying: against the panel and through which the shaft passes. A conductor 23 comprisin the other side of the circuit on which the condenser is used, is connected to the solder plate. The spring thus resiliently presses the knob against the panel and in' sures an electrical connection between the plate 2-2 and the annular ring 4.

From the above it will be clear that the foil plate 8 constitutes one of the condenser plates, the other condenser plate comprising a body of mercury 26 confined in the chamber between the dielectric disk 7 and the housing disk 3. The mercury is introduced into the chamber through an aperture in the disks subsequcuth closed by the plug 27, and the chamberis filled about half full so that the mercury is always in electrical contact with the annular ring 4:.

Since the weight of the mercury causes it to always remain in the lower half of the chamber, that is, in substantially fixed or stationary position, it follows that by relation of the derice. by manipulation of the knob, the semi-circulnrcoudenser plate 8 may be brought into full or pertial registration with the fixed semi-circular eondenser plate 26, or placed-completely-out-of registration therewith, varying the ca acity of the condenser in accordance vi the areas in register. Stop pins 28 on the anel engaged by the arm-29 fixed on the -'db, provlde means for limiting the rotary movementof the device between points of maximum end 'niinimnm chfineiizi' A-eondenseriti accordance with the above description; i of nn'i'ncli thick imii 3 inches in clienieter hast. capacity of approximately .001 xhierdfaw'ds Ibis in 'substentiaily perfeet balance; cannot be short e'irmiited in some ue fis moun ed; ind its construction ieunit'sit tfd :iiahdid Without injury. For demuns'tmien .pil uses, espec'isklliin'sehooljhitioratories; I pl'ze Y the plgie s of mie me mfin the d'v'ioe so that the. altid-"inflii relttidii of. the

we i w i f 'tw me xp identet'.

In Figure 3 Ihlii'eshoi'im a modified bI my coiidensef in which the outer s eei ring- 31 is (if new the rc '11y plate 26 meking-eontaotwith it. I is of lrioh-eondficfihg meter-m1, and the p ate a is eIe trisIij' gesneqtd ha the shift throngh' the geqmmet' With whi'chit is inobnwe.

In Figure 41 have shown a oondenserhaving d fble the of that just describe A di's'k 33 ,sinhliii to dislt 7 is arranged adiwj t hofisi disk 3, and semicii'hier' f ii ate 34, similar to plate 8, is

disposed between he pistes as and a. .The time "mete-at ii -1th ,the sh'eit rmrest of the structure is siixiiiz'u to that alr ady made clear.

I CZ aim:

A vhriehle .wndflnser "rising ii Stetio'n'air'y merc'iirj" condenser phage and a. rotatable condnsei' plate.

2. In .8 ddiidhs'lt, .a rotatable dielectric, .e. condenser plate fi xed .011 one side of said dielectric, and e statienary mercury condenser plate on the other side of said dielectrier 3. A ariable condenser, oinprisings stailimhi-fj m rcury condenser plete, e dielectric disk, :5, condenser plate fixed on said disk, end means for totatinfithe disk .to position the, pldte flied then eon with reference to said merjeqry p rte.

A. variable condenser, comprising s. rottabidhdft a pair ofspaced disks one of which is s rdiiefii ic fixed on the shaft and forming 5i chamber hetnleen the disks, 2. quantity of mercur s' iii said chamber forming one condenser p ate, :i'n'd .a semi-ciy rular condenser pjule fixed on the opposite side of said dieleet i 1 A .viiriyible condenser, comprising a. r0- tatnble shaft, a pair of spaced disks one of site'- si'cle'iif lgiid" dissent disk, a niet a, A vari bie'esnae eecempfising a 0- new share, a ner-"speec es ass of ii h'ih'is dlelee ie fife on tiiesheftaild seeming; a. chiimb-r hetitieeh {he disks a metzrliic for 'spiicin'g tity of r'iie'reiiryin'stiti ehambee in cbn'ta'ct with said ring, a sexht-tiiiciflai oiifle'ri'ser plate on the opposite see oft's'aiid dielectric disk, and fil etflmii cohdhctofseonn d to sell'd ring gm'd to" semi-simmer piste.

7; A variable egndensei, coin}: m gs i=0- one of forn'iihg' ii. 'ii'fiibei Between-the disks 1 frietime r pg m b ag s ec ith ,the h rts ffer e disitfi e dfmnierhpry in said e fiber in coiithct filth'said ring;

disks. and connected to said semi-eitciiler ne sh min .f 'g i n fi .fi b sh ed inreie' circuit tdis'hld a ti the other siti' .to $15113 sflieft.

. s A g'fi'iiihie'condehstan, comprising :1. tbfiatiibie shift, #3 peir 6f aces dislis of which is a dielectric fixe d Ora-the shaft-end fqrrn a chamber betii'eezi'the disks, 5i mes'paq'i' ks, eiji antit y'of inercury in said cu'iiilbi' iii co'i'ltilct ,Wliiii said ring, a semi-circular condenser late on theopfid site s'ic'iedof seiftdieiectfic disk, .:1 mean is rim fer binding the peripheral edges otthe disks and coimecltedte an seiiri-circui'zir electuiccireuit .tmsai and the other side to said shalft', inensi foif-digitiflly itottitiiig said shaft, and meansfor limiting the rotary increment of said shift.

9. A-fiiilliiflblflt condenser, comprising a 1'0- tatahle shift, a pair of hous hg of non-conducting material on said shaft, annular rings'at the center end periphery for ihite means for do ctin .one side of an i i 11 s the disks; e.- quanspacing said .disks' epart the iimer ring he ing. a conduetor hnd the peripheral ring being a non-conductor, n rim of conductlng material for biiiding the peripheral edges of the disk upon the peripheral ring, a grommetpf; conducting" ina'terial died on said shaft for binding the centers of the disks upon the central ring and forming an elec tri'csl connection hefiveen the ring and sziid shaft, :1 dieic'ctric disk interposed between the. rings "(1 bneloithe, housing disks, :1 serni-circuiiii conde'ris r' plate interposed between the dielectric disk and contiguous housing disk and connected to said mm, a, quantity of mercury'disposed between the dielectric disk 1nd the other housing plate and forming contact with said central ring, a knob for turning said' shaft, means for limiting the turning movement of the shaft,

and means for connecting one side of an electric circuit to said rim, and the other side to said shaft. 10

In testimony whereof, I have hereunto set my hand.

JOHN PARKIN, JR. 

